1. Field of the Invention
The present invention relates to a man-machine interface, also referred to as an input device, of the type generally used to manually input control signals to a computer or other data processing systems.
2. Description of the Related Art
Manually controlled signal input devices used with data processing systems often take the form of pointing devices typically including a mouse or joystick. These pointing devices are controlled by a human operator in order to control movement of a cursor on a computer screen, or to control graphic elements on a video game display screen. These pointing devices have commonly taken the form of a rotatable ball, pivoting lever, or push-buttons which serve as control data input means whereby the physical movements of the human operator are converted into corresponding changes in electrical input signals. These electrical signals are then input to a host device, through a signal transmission circuit, as a means of transmitting control data. The host device receives the control data signals and responds by executing a data processing operation which results in the corresponding movement of a graphic element on the display screen.
While the pointing devices are capable of inputting data to the host device in response to physical inputs from the human operator, their response characteristics remain constant even though various operating conditions, such as changes in the display or cursor speed, may fluctuate. As a result, a feeling of direct and natural response is lacking between the operation of the pointing device and corresponding output of the host device as viewed by the graphic conditions displayed on the screen. This lack of natural response results in a non-direct feeling of control and low level of interface between the human operator and the apparatus. As a result, persons unfamiliar or unskilled in the use of a data processing or other computer-controlled devices have trouble adapting to their operation, and often give up before the necessary skill is attained. Furthermore, people who become skilled in the operation of the devices are forced to adapt to the shortcomings of conventional pointing devices, and in doing so expend time and effort in developing a skill which should be unnecessary. As computers and other types of data processing equipment are steadily becoming a more integral part of everyday life in what is becoming an age of multimedia data presentation, it is only reasonable to expect a more direct and natural interface between the human operator and the machine.